Dynamics of a quantum oscillator strongly and off-resonantly coupled with a two-level system

TL;DR

This paper explores the complex dynamics of a quantum oscillator strongly coupled and off-resonantly interacting with a two-level system, revealing phenomena like beatings, collapses, revivals, and spectral doublets beyond the rotating-wave approximation.

Contribution

It provides a detailed analysis of the oscillator's dynamics beyond the rotating-wave approximation, highlighting new phenomena such as beatings and spectral doublets in this regime.

Findings

Beatings with period equal to the two-level system's revival time

Collapse and revival phenomena in oscillator observables

Doublet spectral features in scattered oscillator field

Abstract

Beyond the rotating-wave approximation, the dynamics of a quantum oscillator interacting strongly and off-resonantly with a two-level system exhibit beatings, whose period equals the revival time of the two-level system. On a longer time scale, the quantum oscillator shows collapses, revivals and fractional revivals, which are encountered in oscillator observables like the mean number of oscillator quanta and in the two-level inversion population. Also the scattered oscillator field shows doublets with symmetrically displaced peaks.